RE: [PHP] odd behavior of stripos() with === operator *LAST POST*

At 10:12 AM 11/17/2006 , Ford, Mike wrote: >On 17 November 2006 16:50, Stut wrote: > >> > > Your basic misunderstanding is that === is the opposite of !== >> > > which it's not. > >Complete rubbish -- it so absolutely is! > >If $a===$b, then !($a===$b) is the same as $a!==$b, QED. > > >> > > (INTEGER === true) will always be false because the types >> > > don't match >> > > (INTEGER !== true) will always be true because the types >> > > don't match >> > > (INTEGER === false) will always be false because the types >> > > don't match >> > > (INTEGER === true) will always be false because the types >> > > don't match > >Well, you haven't covered all bases there, you've got INTEGER===true in twice! > >Try this: > > (integer)===TRUE -- is always FALSE > (integer)!==TRUE -- is always TRUE > > (integer)===FALSE -- is always FALSE > (integer)!==FALSE -- is always TRUE Which brings me to the original point of the post, (which is now burried in a heap of discussion) a heads-up to the unwary... If there is any chance that the needle you are looking for in the haystack will be found at the first position (index 0), using === will NEVER return true, do not do this : if ( stripos("abcde","abc")=== TRUE ) {echo "abc found!"} this will NEVER be true. you can however do this: ( (stripos("abcde","abc")!== FALSE) ) { echo "abc found" } in other words do not try to test for === TRUE, only test for !== FALSE and the warning in the manual ... Warning This function may return Boolean FALSE, but may also return a non-Boolean value which evaluates to FALSE, such as 0 or "". Please read the section on Booleans for more information. Use the === operator for testing the return value of this function. should read "...use the !== operator for testing..." because if you use ===, you will NOT get the expected results if needle is found in haystack at position 0. However, !== will always work correctly. > >Looks seriously like two sets of complementary results there to me. > > >> > > The actual value of the INTEGER does not matter. > >True. > >> > > But the basic thing to get clear in your head is that === and !== >> > > are not opposites in the same way that == and != are. > >False, false, false, and a thousand times false. If $a===$b returns TRUE, then $a!==$b returns FALSE; and if $a===$b returns FALSE, then $a!==$b returns TRUE. I don't know how much more opposite you can get. > >Cheers! > >Mike > >--------------------------------------------------------------------- >Mike Ford, Electronic Information Services Adviser, >Learning Support Services, Learning & Information Services, >JG125, James Graham Building, Leeds Metropolitan University, >Headingley Campus, LEEDS, LS6 3QS, United Kingdom >Email: m.ford@leedsmet.ac.uk >Tel: +44 113 283 2600 extn 4730 Fax: +44 113 283 3211 > > > >To view the terms under which this email is distributed, please go to http://disclaimer.leedsmet.ac.uk/email.htm > >-- >PHP General Mailing List (http://www.php.net/) >To unsubscribe, visit: http://www.php.net/unsub.php >